What is the pathophysiology of continuous urinary incontinence?

This severe type of incontinence is characterized by constant or near constant leakage with no symptoms other than wetness. Generally, this represents a significant breech in the storage capabilities of the bladder or urethra. Urogenital fistulas are a classic example.

A nonfunctioning urethra can result in continuous leakage. Scarring and fibrosis from previous surgery, partial urethral resection for vulvar cancer, and urethral sphincter paralysis due to lower motor neuron disease can cause the urethra to fail.

Pelvic irradiation may not only cause urogenital fistula but in rare cases causes bladder noncompliance that results in continuous incontinence. Congenital malformations of the genitourinary tract, such as bladder exstrophy,
[26] epispadias, and ectopic ureters, can result in total incontinence.

Urinary incontinence. Normal findings on urodynamic study of a 35-year-old white man. During the filling cystometrogram (CMG), there is absence of uninhibited detrusor contractions. Bladder compliance is normal. His maximum bladder capacity is 435 mL. During the pressure-flow study, his maximum flow rate (Qmax) is 25 mL/s and detrusor pressure at maximum flow rate (Pdet Qmax) is 50 cm H2O. The uroflow pattern is without abnormality, producing a bell-shaped curve without any abdominal straining. He voids to completion, and the postvoid residual urine is negligible.

Urinary incontinence. Urodynamic study revealing detrusor instability in a 75-year-old man with urge incontinence. Note the presence of multiple uninhibited detrusor contractions (phasic contractions) that is generating 40- to 75-cm H2O pressure during the filling cystometrogram (CMG). He also has small bladder capacity (81 mL), which is indicative of poorly compliant bladder.

Urinary incontinence. Urodynamic recording of bladder outlet obstruction due to benign prostatic hyperplasia (BPH) in a 55-year-old man. Note that during a pressure-flow study, his maximum flow rate (Qmax) is only 6 mL/s and detrusor pressure at maximum flow rate (Pdet Qmax) is very high at 101 cm H2O. He also has a small bladder capacity (50 mL) due to chronic bladder outlet obstruction. His flow curve is flat and "bread-loaf" in pattern, which is consistent with infravesical obstruction.

Urinary incontinence. Urodynamic study revealing detrusor sphincter dyssynergia in a 35-year-old woman with C5 spinal cord injury. Note the absence of uninhibited detrusor contractions during the filling cystometrogram (CMG). Typically, patients with cervical cord lesions manifest detrusor hyperreflexia. However, this patient is taking Ditropan XL. Thus, phasic contractions are suppressed. During the pressure-flow study, note the increase in amplitude of the electromyogram (EMG) coincident with detrusor contraction and voiding. Her uroflow rate is low (1 mL/s), detrusor pressure is high (42 cm H2O), and the EMG recording is elevated.

A cotton swab angle greater than 30° denotes urethral hypermobility. Figure 1 shows that the cotton swab at rest is zero with respect to the floor. Figure 2 shows that the cotton swab at stress is 45° with respect to the floor.

A squirt of urine is observed at the peak of an increase in intra-abdominal pressure in a supine patient

This photo illustrates a variety of pelvic organ prolapses, including grade-IV cystocele, uterine descensus, enterocele, and rectocele alone or in combination. In situations where a significant prolapse (eg, uterus, bladder) has occurred, evaluate for possible ureteral obstruction at the level of the pelvic inlet.

Disclosure: Serve(d) as a speaker or a member of a speakers bureau for: Endo, Avadel.

Acknowledgements

Peter MC DeBlieux, MD Professor of Clinical Medicine and Pediatrics, Section of Pulmonary and Critical Care Medicine, Program Director, Department of Emergency Medicine, Louisiana State University School of Medicine in New Orleans

Mark A Silverberg, MD, MMB, FACEP Assistant Professor, Associate Residency Director, Department of Emergency Medicine, State University of New York Downstate College of Medicine; Consulting Staff, Department of Emergency Medicine, Staten Island University Hospital, Kings County Hospital, University Hospital, State University of New York Downstate Medical Center

Richard H Sinert, DO Associate Professor of Emergency Medicine, Clinical Assistant Professor of Medicine, Research Director, State University of New York College of Medicine; Consulting Staff, Department of Emergency Medicine, Kings County Hospital Center